Also, of notable mention is DDS [1]. It's standardized by OMG (what's not to love about that name?) not IETF.
It's a really interesting pub/sub style IPC. But really it's like a swiss-army knife. CORBA lovers (and haters) will recall IDL, it's used as the description for the interfaces used. IMO the commercial implementations are more feature complete than the open source ones.
If you looked at CORBA in the 1990s and have a sour taste in your mouth, don't hold it against DDS. It's a really great approach. It describes interfaces with a dynamically negiotiated Quality-of-Service among participants. The set of reactions to QoS policy violations effectively create hooks for all of your interesting cases.
IMO DDS works best when all of your participants share a broadcast domain, but it's not necessary to set it up that way.
Service Location Protocol: RFC 2608
RSerPool: RFCs 5351-6